Docker
Env : https://labs.play-with-docker.com/
- Docker = Container and Images
- Docker Can be executed as
- command line
- dockerfile
- docker-compose.yml
Snapshot of the application containing all the libraries , supporting files etc.,
$docker pull python # download new image
$docker images #list all active images saved
$docker rmi -f image_name #delete image , -f force
$docker system prune -a #delete all images + containers
- Containers are similar to virtual machine
- Separate IP Eg: ping container_ip #Talk to host / outside world
- Separate file system
- It has 2 states
- Start
- Stop
- containers share kernel with the host machine.
- Data gets removed if the container is exited / removed.
$docker run -it --name test python:3.7 bash #download + start + go inside
$docker run nginx #download+start
$docker start -i container_id/name #start+go in
$docker exec -it container_id/name bash #go inside
$docker stop container_id/name #STOP
$docker kill container_id/name # STOP
$docker rm container_id/name # Delete
$docker system prune #remove unused images and containers
$docker ps -a #running continaers
$docker cp file_name container:/home/app
$docker logs containeir_id/name
$docker port containeir_id/name
$docker inspect containeir_id/name
$docker attach container_id/name #running container
$docker stats ContainerName/ID #mem,cpu,nw of running container live
$docker version
$docker -v
$docker info
$docker command_name --help
$docker login
$docker pause ContainerName/ID #$docker unpause ContainerName/ID
$docker commit Container new_image_name #convert running container to image
Independent storage outside of container inside
echo "print('hi')" >>test.py
docker run -it --name test -v $PWD:/home/app/ -w /home/app/ python:3.8-slim python test.py #hi
now change the contents of test.py to "print('hello')"
save
docker start -i container_id #hello
1. Command Line docker :
Create a folder
echo "print('hi')" >>test.py
$docker run -it --name test -v ${PWD}:/home/app -w /home/app python:3.9-slim python test.py
2. dockerfile
FROM ubuntu
ARG build_no # input arg
ENV env_var=$build_no # Env var
RUN apt-get update # restarts after installation
RUN apt-get install -y python3
COPY . /home/apps # Copy files to container
WORKDIR /home/apps/ # Default working Directory
EXPOSE 8080/tcp # expose to other containers only , use run/compose for port mapping to outside world
CMD echo $env_var # both CMD and ENTRYPOINT can be used only once. (ENTRYPOINT has higher priority)
3.docker-compose.yml Create another file "docker-compose.yml" (make sure step 2 is done)
-----add below contents----
version: '3'
services:
app:
build: folder\.
--------------------
$docker-compose up
Env : https://labs.play-with-docker.com/
# OS
docker run -d -it alpine bash
docker run -it busybox bash
docker run -it python bash
# Reverse Proxy
docker run -p 8000:80 -v ${PWD}:/usr/share/nginx/html nginx
# Storage
docker run -d -p 5672:5672 rabbitmq # message
docker run -d -p 27017:27017 mongo #result
docker run -d -p 6379:6379 redis
docker run -d -it -p 3306:3306 -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=TestDB -e MYSQL_USER=test -e MYSQL_PASSWORD=test mysql
# mysql -u root -p #root
# show databases;
# pip install PyMySQL
# mysql+pymysql://test:test@0.0.0.0:3306/TestDB
docker run -d -it -p 5432:5432 -e POSTGRES_USER=test -e POSTGRES_PASSWORD=test -e POSTGRES_DB=TestDB postgres
# pip3 install psycopg2-binary
# postgresql://test:test@0.0.0.0:5432/TestDB
# docker -d run --link <postgres_contID>:TestDB -p 8080:8080 adminer
- https://gist.github.com/j-thepac/b5f663612566614b9abc75b6abb607bb [Nginx]
- https://gist.github.com/j-thepac/32b9136bb9d8fa8d243da0123f4a263c [Mongo]
- https://gist.github.com/j-thepac/58192f87b82f79cc27729cd6645678fd [Kafka 1]
- https://gist.github.com/j-thepac/2eb7496c98393331acfc31583e3a59bf [Kafka 2]
- https://gist.github.com/j-thepac/31afe224ea62ffc55274d46be7168d1b [Postgres]
- https://hub.docker.com/_/mysql [MySQL]
1. Python + Volume Mounting
echo "print('hi')" >>test.py
docker run -it --name test -v $PWD:/home/app/ -w /home/app/ python:3.8-slim python test.py #hi
now change the contents of test.py to "print('hello')"
save
docker start -i container_id #hello
2. Redis : Has only Databases from 0-15 (data moved to next db after previous is filled)
docker run --name my-first-redis -d redis #detached mode
docker exec -it my-first-redis sh
$redis-cli
$ping #pong
$INFO #notice 'KEYSPACES'
$ SELECT 0 #select db
$ SET A 1
$ KEYS *
$ GET A
quit
exit
3. Jenkins : https://github.com/j-thepac/HelloWorld
docker run -p 8080:8080 jenkins/jenkins:lts-jdk11
Open localhost:8080
password - in logs\
can also be be inside Jenkins_Home/secrets/initialAdminPass
4. Flask:
#-----flask.py------
from flask import Flask, request
app = Flask(__name__)
@app.route('/')
def hello_world() -> str: return "Hello world"
if __name__ == '__main__':app.run(debug=True, host='0.0.0.0')
#----------
docker run -it --name myflask1 -p 5000:5000 -v ${PWD}:/app python:3.7 bash
pip install flask==1.1.1
cd /apps
export FLASK_APP=flask.py
flask run --host=0.0.0.0
open link : localhost:5000
- Create an empty folder in local machine
- cd to that folder
- docker run -it --name mydjango1 -p 8000:8000 -v ${PWD}:/app python:3.8 bash #open docker terminal
- pip install django==2.2.6 #
- cd /app
- django-admin startproject testsite
- Notice the testsite is created locally
- Under settings.py , add ALLOWED_HOSTS = ['0.0.0.0']
- cd testsite
- python manage.py runserver 0.0.0.0:8000 #ctrl+C to exit
- Now run all steps again and instead of replace #4 with pip install django
- $docker volume create myjenkins
- $docker run --name MyJenkins -p 9090:8080 -p 50000:50000 -v myjenkins:/var/jenkins_home jenkins
- $docker volume ls
- $docker volume inspect myjenkins
- $docker inspect MyJenkins3
docker run -it ubuntu
apt-get update
apt-get install sqlite
sqlite3 test.sqlite3
create table test (id int,name varchar(20));
.tables
.quit
To remove sudo (optional)
(sudo usermod -a -G docker username #to avoid sudo , require start)
sudo chmod -R 777 .docker/
Manager = Worker 1 + Worker2
Open Docker Playground
$docker swarm init --advertise-addr <copy_ip addr from above >
-
copy "docker swarm join --token xx"
-
Open New Instance / Node
-
Paste
$docker swarm join --token xx" -
Go back to Master
$docker service create -d --name nginx -p 8080:80 nginx $docker service update nginx --replicas 3
Test
-
Goto each Node
-
docker ps -a
-
docker logs Commands :
$docker service ps nginx $docker service ls $docker service ps nginx $docker service rollback nginx $docker node ls $docker service ls $docker network ls $docker inspect node1
Ref
https://www.youtube.com/c/AutomationStepByStep
https://www.youtube.com/watch?v=qxPdd-geqqA
